XR6 BA

what does the hot water do and if it’s stops the rough idling then how and what’s causing it I’ve changed coils,plugs,02sensor,I had only put on new keyless pads with keys and did it fords way press rear demister button for three times and when door locks open press each button on each pad so you know they are setup correctly First drive after doing these my car has been idling fine when cold as soon as it’s upto normal driving temperature the car idles very roughly when I put it into neutral it’s okay WHAT IS CAUSING THIS NIGHTMARE OF AN ISSUE SURELY MY CAMSHAFT HASNT GOT THIS LUMPY GRIND IT WOULD HAVE DONE IT PRIOR TO THIS IVE HAD CAR SEVEN YEARS NOW ONLY 112,300klms very good condition